Ukraine's parliament sacked the crisis-hit country's besieged defence minister Tuesday after his forces began a humiliating withdrawal from Crimea without firing a shot against Russian forces who claimed the Black Sea peninsula.

Crimea's effective loss -- though recognised by no Western power -- has dealt a heavy psychological blow to many Ukrainians who have already spent the past years mired in corruption and economic malaise.

Ukraine's ground commanders in Crimea had complained bitterly of confusion among the top brass in Kiev since Russian President Vladimir Putin's decision on March 1 to seek the right to use force against his neighbour in response to last month's fall in Kiev of a pro-Kremlin regime.

Some 228 deputies in the 450-seat Verkhovna Rada parliament supported Igor Tenyukh's dismissal after the acting defence minister tendered his resignation in an emotional address broadcast live to the nation of 46 million people.

"It seems that the actions of the interim defence minister in the Autonomous Republic of Crimea... have displeased some," said Tenyukh.

"I have never clung on to my job, and I don't intend to do so now," he said. "I have honour."

Tenyukh also admitted that 14,500 of Ukraine's 18,800 soldiers in Crimea had informed their superiors they would prefer to remain on the peninsula as part of the Russian military -- a massive majority that underscores the demoralised state of Kiev's force.

Deputies then voted to appoint Lieutenant General Mykhailo Koval as the new acting defence minister after his name was submitted for approval by interim President Oleksandr Turchynov.

Koval had made the news earlier this month when he was briefly abducted by pro-Kremlin militias near his military base in the Crimean port of Yalta.

Tuesday's session gave lawmakers a chance to voice growing frustrations with how the Western-backed leaders have handled their jobs since coming to power on the back of three months of deadly protests whose ultimate aim was to eliminate the corruption and Kremlin dependence that have weighed over Ukraine throughout its post-Soviet history.

"We gave up Crimea to the Russians thanks to our unprofessionalism," independent lawmaker Igor Palytsya fumed. "We gave up Crimea thanks to our indecision."

Tensions between the two neighbours seemed ready spike further when Russian television aired what it claimed was a tape of former Ukrainian premier Yulia Tymoshenko -- an opposition leader released from jail after the pro-Kremlin regime's fall -- urging the "wiping out" of Russians over the seizure of Crimea.

Tymoshenko admitted that her voice was on the tape but insisted that her comments had been manipulated.

- Russia shrugs off G8 snub -

The Crimean crisis has sparked the most explosive East-West confrontation since the Cold War era and fanned fears in Kiev that Putin now intends to push his troops into the heavily Russified regions of southeast Ukraine.

Western leaders sought to ward off any such threat by forging a more forceful response in The Hague after two rounds of only targeted sanctions that hit only specific officials but left Russia's broader economy untouched.

A summit of the Group of Seven most industrialised countries agreed on Monday to deepen Moscow's isolation over the crisis and meet on their own -- without Russia -- in Brussels instead of gathering in Sochi in June.

They also threatened tougher sanctions over Moscow's formal annexation of Crimea last week.

"We're united in imposing a cost on Russia for its actions so far," US President Barack Obama said in reference to the travel bans and asset freezes that Washington imposed on key members of Putin's inner circle last week.

Russia's loss of the right to host the G8 summit is a moral blow to Putin -- a leader whose 14 years in power have focused on resurrecting the Kremlin's post-Soviet pride.

But the Kremlin on Tuesday shrugged off the seven world leaders' decision as "counterproductive" but otherwise harmless.

"When it comes to contacts with the G8 countries, we are ready for them, we have an interest in them," Kremlin spokesman Dmitry Peskov told the ITAR-TASS news agency.

"But the unwillingness of other countries to continue dialogue -- we consider it counterproductive, both for us and for our partners themselves," Putin's spokesman said.

- Urgent aid -

Western powers have been trying to boost the new leadership of debt-laden Ukraine by drumming up urgent assistance that can be issued as soon as the International Monetary Fund puts the finishing touches on a new support programme for Kiev.

The ongoing tensions with Russia have seen Ukraine's currency lose 24 percent of its value to date while yields on government bonds due in June reached stood on Tuesday at about 30 percent -- a figure that makes borrowing prohibitively expensive.

The IMF is expected to put the pieces in place for the first money of a loan of up to $15 billion (10 billion euros) to be issued by the second half of April.

The European Union on March 5 offered to extend its own assistance package of up to $15 billion to Ukraine while Washington has pledged $1 billion in loan guarantees.

Japan pitched in another $1.5 billion to the Ukraine rescue fund on Tuesday.

Moscow's VTB Capital investment house said Tuesday that expectations of an IMF-backed rescue should provide "some support" to Kiev's future borrowing costs.